Locking handle deployment mechanism for medical device and method

ABSTRACT

A system for delivering at least one medical device to a desired location for treatment, and then selectively deploy it in position, includes an improved handle. One of the possible features of the handle may be to selectively hold the delivery system components at any desired configuration during deployment and positioning of the medical device. Another possible feature of the handle may be more than one mode of operation, in which the deployment of the medical device can selectively proceed at more than one speed. Yet another possible feature of the handle may be a locking mechanism that resists inadvertent or accidental movement or retraction of the stent delivery system components during packaging, sterilization, shipping, storage, handling and preparation of the stent delivery system.

REFERENCE TO RELATED APPLICATION

[0001] This patent application is a divisional patent application, ofU.S. patent application Ser. No. 10/175,113 filed on Jun. 18, 2002,which is a continuation-in-part of U.S. patent application Ser. No.09/975,873 filed on Oct. 12, 2001.

BACKGROUND AND SUMMARY OF THE INVENTION

[0002] 1. Technical Background

[0003] The present invention relates generally to medical devices, andmore particularly to a medical device delivery system with an improvedlocking handle having a compound mechanism.

[0004] 2. Discussion

[0005] The present invention involves medical devices, and also thedelivery systems used to convey them to a desired location fortreatment, and then deploy them in position. Many such medical devicesare resiliently compressed to a smaller initial size for containment,protection, storage and eventual delivery from inside a catheter system.Upon deployment, the medical devices may resiliently expand to a largerdeployed size.

[0006] A successful example of a delivery catheter system, in this casefor a self-expanding stent, is described in U.S. Pat. No. 6,019,778entitled “Delivery Apparatus For A Self-Expanding Stent,” to Wilson etal. issued Feb. 1, 2000. The disclosure of this patent is incorporatedby reference in the present application, and generally discloses aflexible catheter system shown in a representative diagrammatic form inFIG. 10, including coaxially arranged inner and outer catheter members,each having a hub affixed to its proximal end. The outer sheath isdescribed in the '778 patent as an elongated tubular member havingdistal and proximal ends, which is made from an outer polymeric layer,an inner polymeric layer, and a braided reinforcing layer between them.The inner shaft is described in the '778 patent as being locatedcoaxially within the outer sheath and has a flexible tapering distalend, which generally extends distally beyond the distal end of the outersheath. The inner shaft member also is shown as including a stop whichis positioned proximal from the distal end of the outer sheath. Aself-expanding stent is located within the outer sheath, and is locatedbetween the stop on the inner shaft member and the outer sheath distalend. To deploy the stent the outer sheath is withdrawn by a physician ina proximal direction, while the inner shaft member is held in position.

[0007] Additional examples of different types of known self-expandingstent delivery systems are shown in U.S. Pat. No. 4,580,568 issued toGianturco on Apr. 8, 1986; as well as U.S. Pat. No. 4,732,152 issued toWallsten et al. Mar. 22, 1988.

[0008] In operation, these known medical device delivery systems aregenerally advanced within a body of a patient along a desired vascularpath or other body passageway, until the medical device within thecatheter system is located at a desired site for treatment. Whilewatching the relative positions of the medical device and the cathetersystem components with respect to a stenosis on a video x-rayfluoroscopy screen, the physician holds the proximal hub attached to theinner shaft member in a fixed position with one hand, whilesimultaneously gently withdrawing the proximal hub attached to the outertubular sheath with the other hand.

[0009] For several reasons, this deployment operation may require somemeasure of delicate skill. For example, among these reasons is thedynamic blood flow at the desired site for treatment, which may befurther disrupted by the presence of a lesion or stenosis to be treated.Another factor is the gradual resilient expansion of a medical device asthe outer sheath is retracted. This gradual expansion presents anopportunity for a possible reverse “watermelon-seed” phenomenon tooccur. This reverse watermelon-seed effect may cause the resilientmedical device to tend to push the outer sheath back in a proximaldirection with a force that tends to change as the sheath isprogressively retracted.

[0010] As a result, the physician may need to accurately hold the twoproximal hubs in a specific relative position, holding them against thisexpansion force, while attempting to very accurately position themedical device up until contact with the anatomy. One of thepossibilities that may affect the positioning of the deployed medicaldevice is that the inner shaft should preferably be held stationary inthe desired position. If the physician's hand that holds the inner shafthub does inadvertently move during deployment, it is possible that themedical device may be deployed in a non-optimum position.

[0011] Another possible factor is that the inner and outer cathetershaft members, like any other elongated object, do not have infinitecolumn strength, which may present an opportunity for the position andmovement of each proximal hub to differ from the position and movementof the respective distal ends of the inner and outer shaft members. Yetanother factor is that the position of the medical device may beadjusted up until the point at which a portion of the expanding portionof the medical device touches the sidewalls of the body passage, so thatthe position of the medical device should preferably be carefullyadjusted until immediately before a portion of the medical devicetouches the anatomy.

[0012] Some known catheter systems require two-handed operation, such asthose with a pair of independent hubs, one hub on the inner and outershaft member, respectively. Other known catheter systems include apistol and trigger grip, with a single mode of deployment, involving asingle trigger pull to deploy the associated medical device.

[0013] Accordingly, although physicians may be capable of operating suchknown systems with great skill, it is desirable to provide an improvedcatheter delivery system capable of facilitating easier and moreaccurate deployment and positioning of resiliently expansive medicaldevice.

[0014] In addition, it is desirable to provide an advanced catheterdeployment mechanism having two modes of operation. In the first mode ofoperation, the delivery mechanism preferably provides a preciselyadjustable link between the inner and outer catheter shaft members, suchthat the relative position of the outer sheath with respect to the innercatheter shaft member can be precisely and selectively adjusted. Yet atany selected position, the delivery mechanism should preferably maintainthis selected relative position of the inner and outer catheter shaftmembers, while resisting any force that may be present tending to movethe inner or the outer catheter shaft members with respect to the other.In a second mode of operation, the delivery mechanism should preferablyenable the physician to rapidly withdraw the outer tubular sheath withrespect to the inner catheter shaft member preferably in a proximaldirection with a single easy motion.

[0015] Moreover, it is desirable to provide an integrated and ergonomichandle for easily and effectively operating the stent delivery system ofthe present invention.

[0016] It is also desirable to provide a handle for operating a stentdelivery system that includes a locking mechanism. Such a lockingmechanism preferably resists inadvertent or accidental movement orretraction of the stent delivery system components during packaging,sterilization, shipping, storage, handling and preparation. The lockpreferably is spring-loaded, or otherwise easily released.

[0017] In addition, the handle mechanism may also provide for activationand retraction of the sheath only, while resisting an attempt tore-advance the sheath and re-cover the medical device.

[0018] Another embodiment of the present invention involves providing asingle actuator for both or all of the multiple modes of operating thehandle and delivery system.

[0019] Additional embodiments of the present invention relate todifferent types of movement to actuate each mode of operation. Forexample, a single actuator may rotate for a first mode of operation, andslide in another mode. Or a single actuator may rotate in one directionfor a first mechanical advantage, and rotate in another direction for adifferent mechanical advantage.

[0020] The present invention accordingly provides such a desirablemedical device delivery mechanism, with an integrated and ergonomichandle replacing the functions of the separate proximal hubs of theprior inner and outer catheter shaft members, providing desired dualmodes of operation as well as the desired locking system.

[0021] These and other various objects, and advantages and features ofthe invention will become apparent from the following description andclaims, when considered in conjunction with the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022]FIG. 1 is an external perspective view of a medical devicedelivery system handle, arranged according to the principles of thepresent invention;

[0023]FIG. 2 is a partial longitudinal cross-sectional view of a medicaldevice delivery system arranged according to the present invention in aninitial configuration;

[0024]FIG. 3 is a partial side elevation view of the medical devicedelivery system of FIG. 2;

[0025]FIG. 4 is a partial top plan cross-sectional view of the medicaldevice delivery system of FIG. 2;

[0026]FIG. 5 is a partial longitudinal cross-sectional view of certaincomponents of a medical device delivery system according to the presentinvention;

[0027]FIG. 6 is a perspective view of certain components of a medicaldevice delivery system according to the present invention;

[0028] FIGS. 7-10 are partial longitudinal cross-sectional views ofcertain components of a medical device delivery system according to thepresent invention; and

[0029] FIGS. 11-14 are perspective views of proximal and distal ends ofa medical device delivery system arranged according to the principles ofthe present invention, in various operating configurations.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] The following description of the preferred embodiments of thepresent invention is merely illustrative in nature, and as such it doesnot limit in any way the present invention, its application, or uses.Numerous modifications may be made by those skilled in the art withoutdeparting from the true spirit and scope of the invention.

[0031] Referring to the drawings, a medical device delivery system isdepicted, with one of the preferred embodiments of the present inventionbeing shown at 10. The illustrated stent delivery catheter system 10 ofcourse depicts only one of many different medical device deliverysystems designs that are within the scope of the present invention. Thepresent invention may be designed to deliver and deploy any suitablemedical device. However, for clarity and convenience, the presentdetailed description will only describe such an example of a deliverysystem for stents.

[0032] Among the possible medical device delivery systems that may beused with the present invention is any appropriate system in which anouter sheath is provided, surrounding an inner shaft. A medical devicemay be carried within the outer sheath during delivery to a desired sitefor treatment, where the outer sheath may be retracted, while the innershaft and medical device are held in place.

[0033] The novel concept of the present invention may also be used formedical device delivery systems in which the motion of the operator todeploy the medical device is selected from any suitable possibility,including axial motion in the proximal direction or distal direction, ora rotational motion, a trigger actuator, a gear mechanism, or any othertype of actuator that may be preferred, depending upon a particularapplication. Indeed, the present unique concept may be used for medicaldevice delivery systems in which the medical device is deployed in anysuitable manner, including retracting an outer sheath in a proximal ordistal direction, or uncovering a medical device in various ways,including withdrawing portions of outer sheath members in proximal anddistal directions, simultaneously or sequentially.

[0034] The present invention may preferably have several advantagesindividually, or any combination of such advantages, including forexample: (i) single-handed operation of the medical device deliverysystem; (ii) a mechanism providing leverage or mechanical advantage, toadjust or reduce the forces needed to operate the system; (iii) improvedaccuracy in positioning the medical device during deployment; and (iv)multiple operational modes of operation, including for example a firstmode of fine and precise control of the deployment process, and a secondmode of rapid and easy deployment.

[0035] Moreover, additional advantages may include: (i) an integratedand ergonomic handle for easily and effectively operating the stentdelivery system of the present invention; (ii) a locking mechanismcapable of resisting inadvertent or accidental movement or retraction ofthe stent delivery system components during packaging, sterilization,shipping, storage, handling and preparation; and (iii) a capability ofholding the delivery system components in a fixed relative positionduring an intermediate point in deploying a medical device.

[0036] The particular embodiment of the present invention selected forillustration in the drawings includes a handle 10, shown in detail inFIGS. 1-10. An upper and lower main body housing 12 and 14 are arrangedin a top-and-bottom configuration, as shown for example in FIGS. 1 and3. Other components include inner and outer shaft members 16 and 18respectively, an anchoring member 20, a proximal hub 22 with an actuatoror knob 24 and a corresponding flush lumen tube 26, as well as athreaded base member 30 and a rotating finger ring 32.

[0037] In addition, the handle of the present invention preferably has alocking mechanism 28 for releasably locking the outer shaft member 18 inan initial position relative to the handle 10 and the inner shaft member16, by resisting movement of the rotating finger ring 32 relative to theupper and lower body housings 12 and 14, and thus preventing motion ofthe threaded base 30 and proximal hub 22.

[0038] The lower main body housing 14 preferably has several grippingknurls 34 for providing a physician with a good gripping surface, whilethe upper main body housing 12 has a longitudinal slot 36 defining achannel for sliding the movable actuator 24 and thus limiting the extentof possible travel for the actuator 24 and proximal hub assembly 22.Together, the upper and lower body housings 12 and 14 define openings 38through which a physician can operate the rotating finger ring 32, aproximal anchoring aperture 40 adapted to capture a portion of theanchoring member 20, a distal shaft aperture 42 through which the innerand outer shaft members 16 and 18 extend, and several internal openingsfor receiving fasteners 44 to hold the main body housings 12 and 14together. They also define a circular annular bearing shelf or shoulder46.

[0039] In the preferred initial configuration, proximal hub 22 isaffixed to threaded base 30, which rotatably carries rotating fingerring 32. A distal surface of rotating finger ring 32 touches and bearson shoulder 46 of main body housing 12. Rotation of the rotating fingerring 32 causes it to press on shoulder 46 and pull on threaded base 30,resulting in very precise and sensitive withdrawing movement of outershaft member 18 in a proximal direction. Then, when more rapid proximalwithdrawal of the outer shaft member 18 is desired, the physician maygrasp the actuator 24 and swiftly draw the hub 22 directly back in theproximal direction.

[0040] In the particular assembly shown in the drawings, main bodyhousings 12 and 14 are held together by fasteners 44. Anchor aperture 40fixedly receives anchor 20, which is affixed to the proximal end ofinner shaft member 16. A proximal end of outer shaft member 18 isaffixed to proximal hub 22, with a flexible strain relief 48 protectingthe joint.

[0041] An example of operating the medical device delivery system of thepresent invention is graphically depicted in FIGS. 11-14, which includeillustrations of a handle 54 having a different appearance than handle10 shown in FIGS. 1-10. In operation, the distal end 56 of the medicaldevice delivery system is preferably directed into a patient via a bodypassageway. The medical device delivery system may preferably followalong a guidewire (not shown), and/or travel through a previously placedguiding catheter (not shown), until the distal end 56 is at a desiredlocation for treatment. As shown in FIG. 11, the distal tip 56 haspreferably crossed the site of a lesion or stenosis 58. When the deviceis properly in an initial position, the physician releases or breaks offthe lock of the present invention. A single embodiment of the lock isillustrated in FIGS. 1 and 4, and of course the present inventionencompasses a multitude of various lock configurations, including pins,clamps, breakable members, spring-loaded locks, splines, or keys. Thelock may be releasable only once, or may be capable of repeatedly beingengaged and released. For example, the lock shown in FIGS. 1-10 may beinitially released by squeezing the components, and then used to re-lockthe system in another position or configuration, such as for examplethat shown in FIG. 13.

[0042] Such a locking mechanism preferably resists inadvertent oraccidental movement or retraction of the stent delivery systemcomponents during packaging, sterilization, shipping, storage, handlingand preparation.

[0043] After the lock is released, the preferred operation of thepresent invention may be accomplished by first rotating the finger ring60 to cause it to advance on threaded base 62 and press against shoulder64, such that the entire assembly of threaded base 62, proximal hub andouter shaft member 66 withdraw proximally with respect to handle 54, andthus with respect to inner shaft member 68. This first method ofwithdrawing the outer sheath 66 allows precise and sensitive adjustment.

[0044] As shown in FIGS. 11 and 12, the physician may rotate the fingerring 60 slightly, to pull the outer sheath 66 back slightly. This smallmovement exposes a small portion of the medical device, in this case astent 50, as shown in FIG. 12. In this configuration, the handle of thepresent invention will hold the outer sheath 66 in position relative tothe inner body 68, resisting further inadvertent expansion of the stent50. The physician then has the time and flexibility of procedure toselectively optimize and make any final adjustments to the position ofthe medical device and delivery system within the desired site, asillustrated by the arrow in FIG. 12. This precise adjustment of theposition of the stent 50, before any portion of the stent 50 touches thebody passage or vessel 70 in a manner that might inhibit furtherpositional adjustment, is preferable.

[0045] When the physician is satisfied with the positioning, as itappears on a fluoroscopic x-ray video screen, the physician may continueto rotate the finger ring 60 to further withdraw the outer sheath 66, asshown in FIG. 13.

[0046] Upon initial contact of the stent 50 with the vessel wall, orwhen the stent is 5 expanded sufficiently to independently hold itsposition, or at any desired point, the physician may simply grasp knob72 and pull or push it along slot 74, as depicted by the arrow in FIG.14. This second method of withdrawing the outer sheath 66 allowsrelatively large-scale and rapid movement, at whatever speed thephysician wishes, to quickly deploy the medical device.

[0047] Various materials may be selected for the components of thepresent invention, including any material having the desirableperformance characteristics. In the particular embodiment shown in thedrawings, the inner and outer shaft members 16 and 18, strain relief 48,and distal tip 56 may be made of any biocompatible and suitably flexibleyet sufficiently strong material, including polymers of various types.Possible selections for such materials include nylons or polyamides,polyimides, polyethylenes, polyurethanes, polyethers, polyesters, etc.In the alternative, some portion or all of the inner and/or outer shaftmember 16, 18 may be formed of a flexible metal, including for examplestainless steel or nitinol hypotube. The stent 50 is preferably made ofany biocompatible material that is strong and rigid, including forexample stainless steel, platinum, tungsten, etc. The components of thehandle of the present invention are preferably made of a material thatis strong and rigid, including for example inflexible polycarbonates, oreven some metal components.

[0048] Of course, many different variations are included within thescope of the present invention. Some of these variations or alternativeembodiments include any possible arrangement of sizes, materials, anddesigns within the bounds of the following claims.

[0049] In addition, the inner shaft member 16 assembly, including anchor20, inner shaft member 16 and distal tip 56, may preferably be providedwith a through lumen adapted to receive a guidewire.

[0050] It should be understood that an unlimited number ofconfigurations for the present invention could be realized. Theforegoing discussion describes merely exemplary embodiments illustratingthe principles of the present invention, the scope of which is recitedin the following claims. Those skilled in the art will readily recognizefrom the description, claims, and drawings that numerous changes andmodifications can be made without departing from the spirit and scope ofthe invention.

What is claimed is:
 1. A medical device delivery system fortherapeutically treating a patient, comprising: an inner shaft, havingproximal and distal ends; a tubular outer sheath, at least a portion ofwhich surrounds a portion of the inner shaft member; a medical devicewithin the outer sheath in an initial configuration; a handle affixed tothe inner shaft and operatively coupled with the outer sheath; a firstand second independently movable actuator for adjusting the relativepositions of the inner shaft and the outer sheath, each of the first andsecond actuators providing a different amount of mechanical advantagebetween an input to one of the first and second actuators by a physicianand a resulting relative position of the inner shaft and the outersheath respectively; and a locking member that releasably holds theouter sheath relative to the inner shaft in an initial configuration,thereby holding the outer sheath in the initial configuration andtending to resist inadvertently uncovering the medical device.
 2. Themedical device delivery system of claim 1, wherein the locking memberhas first and second surfaces, such that in the initial configurationthe first surface releasably holds a component attached to the outersheath, and the second surface releasably holds a portion of the handle.3. The medical device delivery system of claim 1, wherein the lockingmember has one or more flanges that releasably resist movement of one ormore of the first and second actuators.
 4. The medical device deliverysystem of claim 1, wherein the first actuator provides a mechanicaladvantage of 1:1.
 5. The medical device delivery system of claim 1,wherein the first actuator is adapted to slide along a longitudinal slotdefined by the handle.
 6. The medical device delivery system of claim 1,wherein the second actuator provides a mechanical advantage greater than1:1, to facilitate an operator to overcome initial resistance tochanging the initial relative position of the inner shaft and the outersheath.
 7. The medical device delivery system of claim 1, wherein thesecond actuator is adapted to rotate around a threaded base.
 8. Themedical device delivery system of claim 1, wherein the second actuatorprovides a variable mechanical advantage that can be selected by anoperator from among a pre-selected range of possible mechanicaladvantages.
 9. The medical device delivery system of claim 1, whereinone of the first and second actuators is formed as a lever.
 10. Themedical device delivery system of claim 1, further comprising aguidewire lumen for slidably receiving a flexible guidewire.
 11. Themedical device delivery system of claim 1, wherein the medical device isa stent.
 12. The medical device delivery system of claim 11, wherein thestent is of the self-expanding type.
 13. The medical device deliverysystem of claim 1, wherein the first and second actuators are movablymounted to the handle.
 14. A handle for manipulating a medical devicedelivery system for therapeutically treating a patient, comprising: ahousing; first and second shaft members; the first shaft member beingaffixed to the housing; the second shaft member being movably coupled tothe first shaft member, such that the second shaft member can be movedlongitudinally with respect to the first shaft member; first and secondindependent means for selectively moving the second shaft member withrespect to the first shaft member; the first means being adapted forprecise and sensitive adjustment of the position of the second shaftmember, and the second means being adapted for rapid and relativelylarge-scale movement of the second shaft member; and a locking memberthat releasably holds the first and second shafts in a constant initialrelative position.
 15. A handle for manipulating a stent delivery systemto therapeutically treat a patient, comprising: a housing having a slotand a drive shoulder; inner and outer shaft members; the inner shaftmember being affixed to the housing; at least a portion of the outershaft member surrounding a portion of the inner shaft member, such thatthe outer shaft member can be moved longitudinally with respect to theinner shaft member; a hub assembly affixed to a proximal end of theouter shaft member and being longitudinally movable within the housing;the hub assembly having a grasping knob and a threaded drive member; thegrasping knob extending outward through the housing slot; wherein thehub assembly may be directly moved in a longitudinal direction relativeto the inner shaft member by pulling on the grasping knob; a rotatableactuator having a bearing surface and being mounted about the threadeddrive member in threaded engagement; such that rotation of the actuatorin a selected direction about the threaded drive member causes therotatable actuator to press on the bearing surface, thereby pulling in aproximal direction the threaded drive member, hub and outer shaftmember; whereby the position of the outer shaft member relative to theinner shaft member may be adjusted by the rotatable actuator in aprecise and sensitive manner, while movement of the grasping knob causesrapid and relatively large-scale movement of the outer shaft memberrelative to the inner shaft member; and a locking member that releasablyholds the inner and outer shafts in a constant initial relativeposition.